Trick play (or trick mode) features allow for operations such as forward and reverse play at multiple rates. Such features may be provided by skipping or duplicating frames of a video, or by adjusting the playback frame rate. For example, in fast-forward and fast-reverse at a 2× rate, a system may provide the appearance of playing the video at double rate (forwards or backwards) by skipping playback of every other frame (e.g., the frames are displayed at the same rate, but only half the frames are presented), or by presenting every frame at twice the playback rate. Similarly, slow-forward and slow-reverse at a ½ rate provides the appearance of playing the video at half rate by displaying every frame twice (e.g., the frames are displayed at the same rate, but twice the frames are presented), by generating new frames in between the original frames, or by presenting every frame at half the playback rate. For skip-forward and skip-reverse, the system simply skips display of a duration of the video timeline (i.e., skips a predetermined number of frames) before returning to normal playback.
These and other trick play features provide the viewer a search capability to advance or reverse the playback timeline of the content to a point where the viewer would like to begin or resume watching the content at a normal playback rate (e.g., skipping a commercial). The trick play features, however, substantially limit and may entirely eliminate the viewer's ability to experience as intended (e.g., comprehend) the content during use of these trick play features. For one, the audio that is synchronized to the video may not have an analogous capability to simply skip (or duplicate) a slice of the audio corresponding to the skipped or duplicated frames. Were this to occur, the audio would become incomprehensible. For this reason, playback of the audio is often suspended during trick play.
To provide a viewer a better experience, there remains a need to be able to present audiovisual content at an adjustable rate desired by the viewer, but in a manner that remains comprehensible.